1. Field of the Invention
The present invention relates to an integrated-inverter electric compressor that is constructed by installing an inverter in an inverter box provided at a periphery of a housing and that is particularly suitable for use in a vehicle air conditioner.
This application is based on Japanese Patent Application No. 2010-020206, the content of which is incorporated herein by reference.
2. Description of Related Art
Recently, in addition to automobiles that run on internal combustion engines, development and market introduction of vehicles that run on electric power, such as electric vehicles, hybrid vehicles, and fuel-cell vehicles, are advancing rapidly. In many air conditioners for such vehicles that run on electric power, electric compressors driven by electric motors that operate using electric power are used as compressors that compress refrigerant and feed the compressed refrigerant.
Also with air conditioners of automobiles that run on internal combustion engines, there exists a type in which, instead of a compressor that is driven via an electromagnetic clutch by the internal combustion engine for running, an electric compressor is used in order to avoid degradation of driveability caused by engagement and disengagement of the electromagnetic clutch.
As such an electric compressor, a hermetic electric compressor in which a compressor and an electric motor are provided together inside a housing is employed. In particular, an electric compressor in which electric power supplied from a power source is supplied to the electric motor via an inverter and the rotation speed of the compressor can be controlled to vary in accordance with the air conditioning load is often employed.
According to some proposals that have hitherto been made, in such an electric compressor driven via an inverter, a control circuit board or the like constituting the inverter is accommodated in an inverter box formed integrally at the periphery of a housing of the electric compressor, thereby integrating the inverter with the electric compressor, and electrical components such as a smoothing capacitor that suppresses ripple of a current supplied to the control circuit board or the like, a switching element, and a reactor are accommodated in the inverter box (e.g., see Japanese Unexamined Patent Application, Publication No. 2008-252962 and the Publication of Japanese Patent No. 3818163).
In the integrated electric compressor according to Japanese Unexamined Patent Application, Publication No. 2008-252962, as disclosed in FIGS. 1, 3, and 4 of the document, in an inverter box, a capacitor is disposed vertically at a position not overlapping a control circuit board of an inverter, and the capacitor is electrically connected to the control circuit board via a busbar.
In the integrated electric compressor according to the Publication of Japanese Patent No. 3818163, as disclosed in FIGS. 7 and 8 of the document, a control circuit board of an inverter is installed in an inverter box formed integrally at the periphery of a housing, and electrical components are disposed in a dead space formed between the bottom face of the control circuit board and the periphery of the housing constituting the bottom face of the inverter box.